1. Field of the Invention
This invention relates to methods and microscopes for measuring the difference(s) between at least two energy path lengths.
2. Description of the Related Art
Conventional microscopes have a large depth of field or axial resolution compared to their lateral resolution. Confocal microscopes have approximately 30% better lateral resolution and much better axial resolution than conventional microscopes. To get high lateral resolution surface profiles of objects it is common to use an interference microscope. It would be advantageous to combine the properties of an interference microscope with those of a confocal microscope. Standard confocal microscopes suffer from alignment problems and require large numbers of components precisely located with respect to each other on an optical bench arrangement. Confocal interference microscopes also have severe stability problems due to such things as air currents and minor temperature fluctuations. In addition, a normal interference confocal microscope has a very limited depth of field and is difficult to scan rapidly.